Build Your Own Combat Robot

FIGURE 11-6
Semiautonomous
weapons systems
diagram.
Semiautonomous Weapons
Chapter 11: Autonomous Robots 251
A semiautomatic weapon system is a valuable method that can be used to overcome
this distraction and experience problem. Figure 11-6 shows a simplified schematic
that demonstrates how to implement an automatic weapon system, such as a hammer
or a spike. The system uses a proximity or range sensor such as the Sharp
GP2D05 range detector. This sensor is designed to trigger a signal when the opponent
gets within 24 inches of your robot. The output from this sensor is fed into a
microcontroller that turns on the H-bridge that drives the weapon’s motor.
A limit switch on the robot tells the microcontroller that the weapon completed
its range of motion and that the motor needs to be reversed to retract the weapon.
For safety purposes, the microcontroller must be connected to the radio control
(R/C) equipment’s receiver. The microcontroller must shut off the automatic
weapon feature if it loses a command signal from the receiver. To enable a manual
weapons control, the microcontroller can be used to control a single-pole double-throw
(SPDT) relay that can bypass command signals between the receiver
and microcontroller to the weapons motor controller.
With the automatic weapon system activated, all you have to concentrate on is
positioning your robot against your opponent, and you can let the internal robot
brain control the weapon for precise attacks. When you run up against a wall, you
can quickly disable the automatic weapon system so that your robot doesn’t attack
the walls. And when the time arises, you can still manually attack your opponent.
Implementing Semiautonomous Target Tracking
The next level of semiautonomous control is to implement semiautonomous target
tracking. With this type of system, you can simply drive your robot close to